One bottle to rule them all...

These guys get it. No single beer can fully capture a state or region's beer scene, but I'd be hard pressed to argue against Ale Apothecary or Peche 'n Brett as great examples of "no one else in the country can do it quite like this." Fruited stuff from pFriem, de Garde, or Upright are other good candidates too, but showcasing regional fruit or other flora is probably the best way to accomplish what you're after in a single can/bottle.

 

This is the correct answer

 

This is also the correct answer but too hard to find usually

 

Go get a 4 pack of Double Stack at Great Notion's Saturday release. Your friends in Minnesota will love you forever. More Orange Creamsicle this Saturday also, but not sure how well that will hold up if you don't drink it right way.

 

Rusty Nail hasn't yet been mentioned, but it is one of the finest BA stouts this region has ever produced. And it just so happens to be currently available. While there's nothing about it that's endemic to the Pacific Northwest, and it doesn't exactly scream (or even whisper) local terroir, it is nevertheless a shining example of extraordinary craftsmanship. A special occasion beer which is more than capable of serving as an ambassador for the outstanding brewing and barrel-aging being done in this beautiful corner of the globe.

 

I haven't been looking for it, but I don't think it will be an easy find here in Portland. Possibly more available in Vancouver.

 

OK, after rereading the OP, and giving it some thought, here we go.

The best selling beer isn't packaged, Mac n Jacks African Amber, so that's off the table here. The beer style that captures the PNW is almost certainly the IPA. We grow the hops, and hops are likely our defining "terrior".

Which one though? I think it should be from an established brewery (at least 10 years, and preferably 15). Because they don't meet my 10 year minimum, the Bronze medal goes to any of Bale Breakers 4 canned IPAs: F41, Leota Mae, Top Cutter, and Bottom Cutter.

Silver medal goes to Silver City's St. Florian

Gold wasn't even close: Georgetown Bodhizafa.

Any of the above beers capture what it means to have "a beer" in the 18 years I've lived here.

 

OP mentions Portland so precludes anything unique to Seattle. Gotta be Oregon. How about Logsdon Seizoen Bretta? I would recommend Peche ‘n Brett but hard to find.

 

Only thing I see different is availability. To define the NW beer scene in my time here, it should be a beer commonly on tap and available in packages.

If Barley Browns or Boneyard were readily available, across our region, they would certainly be in the mix for gold medal here.
However, I think time is an important component in what would describe "US", beerwise.

Honestly, Alaskan Amber is worthy of discussion, in my eyes, of a beer that describes US. Let alone Black Butte, Mirror Pond, Abyss, and a bunch of other stuff Deschutes.

As are a so many beers from so many other breweries . Le Shrug. Milages vary.

 

I have traveled with beer pretty much every time I've flown the past 10 years or so. I have not lost a single can, crowler, or bottle, either to breakage or to the TSA.

While I understand a bit of your anxiety due to the fact that you're pinning your hopes on a single bottle, I really don't think you have anything to worry about.

Also: John's right. You can't take that much liquid through security in carry-on luggage. The alternative is to make your purchases at PDX after you've cleared security. But while I'm one of the biggest cheerleaders when it comes to the beer selection at PDX, that's not your best option unless it is that important to you to have the bottle with you on the plane.

 

Likewise, never a problem to date with TSA (knocks on wood). Also definitely echo the sentiments for Pallet Jack, if I could only choose 1 IPA for the rest of my life, its the one.

While Orange Creamsicle isn't for every palate, I love that beer! But have no data points for its longterm stability.

You've got a plethora of options which will undoubtedly treat you well!

 

It's already pretty much here-and-gone out here in the wilds of Spokane. I've heard fewer were bottled this year.

 

Probably not helpful to OP, but it is still available in Eugene.

 

I saw some this afternoon at New Seasons Cedar Hills, behind the counter at their beer & wine bar. I picked up one bottle, looked like there were 4 or 5 left.

(Off-topic: I also spotted 4-packs of La Cumbre Elevated IPA. A nice, tasty surprise.)